parenting_cj2020_notworking

def check_clash(person_schedule,activity_num,activities):
    for person_activity in person_schedule:
        print(str(person_activity) + ", " + str(activity_num))
        if check_activity_clash(activities[person_activity],activities[activity_num]):
            print ("Events " + str(person_activity) + " and " + str(activity_num) + " clashes.")
            return True
        print ("Events " + str(person_activity) + " and " + str(activity_num) + " does not clash.")
    print("Event " + str(activity_num) + " added to activity list " + str(person_schedule))
    return False

def check_activity_clash(activity,activity2):
    return activity[1] > activity2[0] and activity2[1] > activity[0]

test_cases = int(input())
for test_case in range(test_cases):
    num_activities = int(input())
    impossible = False
    activities = []
    c = []
    j = []
    for a in range(num_activities):
        temp_line = input().split()
        int_temp_line = list(map(int,temp_line))
        activities.append(int_temp_line)
    for i in range(num_activities):
        if check_clash(j,i,activities):
            if check_clash(c,i,activities):
                impossible = True
                break
            else:
                c.append(i)
        else:
            j.append(i)
    if impossible:
        print("C: " + str(c))
        print("J: " + str(j))
        print("Case #"+str(test_case+1)+": IMPOSSIBLE")
    else:
        output = ""
        for k in range(num_activities):
            if k in c:
                output = output + "C"
            elif k in j:
                output = output + "J"
        print("Case #"+str(test_case+1)+": " + str(output))